Xiao Li is said _________ abroad, but I don’t know what country he studied in.

A．to study

B．to be studying

C．to be studied

D．to have studied

婚姻家庭伦理的基本规范：（1）（）（2）男女平等（3）夫妻和睦（4）勤俭持家（5）邻里团结。